Yogic pranayama

The Lunar Channel

Beginner

Left nostril breathing to calm and cool the body

8 min
Begin
overheated moonlit

Why this practice

The left nostril activates the parasympathetic branch and right hemisphere, lowering body temperature and heart rate. The extended exhale amplifies the effect. Excellent before sleep or when the mind is running hot.

Source current

Breathing exclusively through the left nostril — closing the right with a finger — is said to activate the cooling, calming side of the nervous system. Called Chandra Bhedana (moon-piercing) in Sanskrit, research links left-nostril breathing to greater parasympathetic activation: less heat, more ease and inward focus.

The science behind it
Breathing only through the left nostril (as in Chandra Bhedana) engages mechanisms that favor parasympathetic activity — the “rest-and-digest” branch of the autonomic nervous system. Nasal airflow is not neutral: the two nostrils alternate dominance (the nasal cycle), and unilateral breathing practices can shift neural activity and heart-rate variability in ways that support calm states. An extended, slow exhale further biases the system toward parasympathetic tone because vagal outflow is strongest during the out-breath, which lowers heart rate and promotes relaxation.

Physiologically, slow, gentle breaths and short comfortable holds subtly alter CO2 levels in the blood. Keeping the practice soft (no forceful hyperventilation) helps maintain healthy CO2 — avoiding the anxiety-linked effects of over-breathing — and supports the baroreflex and vagal feedback that regulate heart rate and blood pressure. Psychologically, focusing on the left-nostril flow strengthens interoception (the sensing of internal body signals), which helps shift attention away from rumination toward embodied cues of safety and drowsiness, making this practice useful before sleep or when trying to cool an agitated mind.
Sources and references
  • Article

    How Breath-Control Can Change Your Life: A Systematic Review on Respiratory Modulation of Brain Function

    A. Zaccaro, A. Piarulli, M. Laurino et al.

    Systematic review summarizing how different breathing patterns (including slow breathing) influence autonomic function, brain activity, and emotional state.

  • Book

    Breath: The New Science of a Lost Art

    James Nestor

    Accessible synthesis of modern and traditional breathing practices, including discussion of nasal breathing, CO2, and health effects.

  • Article

    Relaxation techniques: Breath control may help quell errant stress response

    Harvard Health Publishing

    Practical overview of how breathing techniques and slower exhalation can reduce stress and support parasympathetic activity.

  • Book

    The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation

    Stephen W. Porges

    Foundational work on how vagal pathways mediate safety, social engagement, and physiological states — useful context for understanding breath-driven parasympathetic shifts.

Breathing rhythm

Lunar breath
8 min
Inhale
6s
Hold
2s
Exhale
8s
Pause
0s

Ring finger closes the right nostril on the inhale. Thumb closes the left nostril on the exhale. Breathe only through the lunar channel.

Inhale left nostril, hold softly, exhale right nostril. Repeat.

How to practice

  1. Sit or lie down. Bring the right hand to Vishnu Mudra.
  2. Close the right nostril with the thumb.
  3. Inhale slowly through the left nostril for 6.
  4. Hold softly for 2. No strain.
  5. Close the left nostril with the ring finger and release the thumb.
  6. Exhale fully through the right nostril for 8.
  7. Inhale again only through the left. Keep the right closed throughout the inhale.
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